牟宗三先生對朱子思想衡定為心性情三分，理氣二分。朱子所說之理為只存有而不活動，故朱子為他律的倫理學。本文試圖論證朱子之言持敬工夫時，是有良心發見作為根源的動力；又從朱子弟子陳北溪所說「心是理氣之合」之義，說明朱子所說的心的活動中，有性理直接起作用之可能，由是而對朱子的哲學做出一新的詮釋。

Professor Mou, Tsung-San's interpretation of Zhu, Xi's thought is Xin-Xing-Qing Mind-Human Nature-Emotion trichotomy and Li-Qi (Principle-material force) dichotomy. The Principle of Zhu, Xi's can be characterized as the being which is to be but not to act. From this point of view, we can characterize Zhu, Xi's ethics as herteronomous. In this paper I try to argue that Zhu, Xi's theory of Respect has its foundation of conscience (good heart). At the same time, according to Chen, Bei-Xi's ”mind as synthesis of Li-Qi,” I try also to argue that the the activity of mind in Zhu,Xi's theory is that a principle has its possibility of functioning by itself. After these considerations I hope I will make a new interpretation on the philosophy of Zhu, Xi.